A wind turbine gearbox helps increase slow rotational speed of the rotor to a high speed motor to generate electricity.

1. K.J.SOMAIYA COLLEGE OF ENGINEERING
(An Autonomous College Affiliated to University of Mumbai)
UMEL502 – THEORY OF MACHINES II
Experiment 3 – Analysis of Gearbox.
WIND TURBINE GEARBOX.
AMAN NILESH HINDOCHA.
A4 BATCH.
T.Y.MECH A.
1825005.

2. INTRODUCTION -
• A wind turbine effectively transfers kinetic energy harvested
from wind to mechanical energy that drives a rotor, which
coupled with a gearbox drives a motor to generate electricity.
• A wind turbine gearbox helps increase slow rotational speed
of the rotor to a high speed motor to generate electricity.
• The gearbox is an important part of a wind turbine. It
provides system motion that is essential for wind power
generation. Therefore, the condition of a gearbox shouldn’t be
neglected.

5. FUNCTION -
• With a gearbox you convert between slowly rotating, high torque power
which you get from the wind turbine rotor – and high speed low torque
power, which you use for the generator.
• A gearbox is typically used in a wind turbine to increase rotational speed
from a low-speed rotor to a higher speed electrical generator.
• The main function of gearboxes in wind turbine systems is rotation speed
regulation and efficiency improvement. In order for the compact electric
generator to work well, some parts must move extremely quickly, since
generated voltages depend on how much power a wind turbine produces.
However, the turbine blades themselves cannot move very fast because of
centrifugal forces. Thus, a gearbox is needed to increase the speed of
rotation of the slow turbines to faster generator turns.

6. WORKING -
• In traditional gearbox-operated wind turbines, the blades spin a shaft that is
connected through a gearbox to the generator. The gearbox converts the turning
speed of the blades—15 to 20 rotations per minute for a 1 MW turbine—into
about 1,800 rotations per minute that the generator needs to generate electricity.
• The gearbox in a wind turbine dose not change gears. It normally has a single gear
ratio between the rotation of the rotor and the generator. For a 600 to 750 kW
machine, the gear ratio is typically approximately 1 to 50.
• Gearboxes are usually built using planetary gearing system, and are equipped with
several auxiliary system.

8. MATERIAL -
• Usually, wind turbine gearboxes are made of steel, aluminum or
brass. Other material may also be used. All wind turbine gearbox
types have their unique form and special features. These facts are very
important to remember for proper gearbox oil maintenance.
LUBRICATION -
• Mineral oil and different synthetic oils such as poly-alfa-olefine
(PAO), poly-alkyleneglycole (PAG) and esters are common lubricants
in gearboxes. The fluid properties should preferably suit the entire
gearbox.

9. REQUIREMENTS -
• The gearbox must survive over 20 years with very high, cyclical loads.
• Gearboxes should be as silent as possible.
• Gearbox have low vibrations and dissipate quickly the heat produced
by the internal mechanisms.

10. SMALL & MEDIUM WIND TURBINE
GEARBOXES - SBH 410/S & SBH 280/80
Wind Mill
Gearbox
SBH 410/S SBH 280/80
Power 250 kW 55 kW
Turbine Speed 41.5 rpm 58 rpm
Generator Shaft
Speed
1515.6 rpm 1031.2 rpm
Speed increasing
Ratio
1 / 36.521 1 / 17.778
Weight 1800 kg. approx. 675 kg. approx.
Technical Specifications